Node axios: From 1.15.0 until 1.20.0, Axios shouldBypassProxy applies a quadratic trailing-dot regular expression to redirect hostnames. (CVE-2026-101906)
Description
Axios versions from 1.15.0 up to but not including 1.20.0 contain a vulnerability in the shouldBypassProxy function where a quadratic trailing-dot regular expression is applied to redirect hostnames. When HTTP_PROXY or HTTPS_PROXY is configured with a non-empty NO_PROXY or no_proxy, and redirects are followed, a crafted redirect Location header containing many dots followed by a non-dot character can cause the hostname.replace regular expression to backtrack quadratically. This synchronous regex processing can block the Node.js event loop, resulting in a denial of service. The issue is fixed in version 1.20.0.
CVSS v4.0
Affected software
pkg:deb/ubuntu/node-axios?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/node-axios?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/node-axios?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/node-axios?arch=source&distro=stonkingpkg:deb/ubuntu/node-axios?arch=source&distro=esm-apps/resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Axios, a promise-based HTTP client for Node.js and browsers, has a denial of service vulnerability in versions 1.15.0 through 1.19.x due to inefficient regular expression processing in the shouldBypassProxy function. Specifically, when proxy environment variables are set and redirects are followed, a maliciously crafted redirect hostname with many trailing dots can cause the regex to backtrack quadratically, blocking the Node.js event loop synchronously. This leads to a denial of service condition. The vulnerability is resolved in Axios version 1.20.0.
Potential Impact
An attacker can cause a denial of service by triggering synchronous, quadratic-time regular expression processing in Axios when handling crafted redirect hostnames under certain proxy configurations. This blocks the Node.js event loop, potentially making the application unresponsive.
Mitigation Recommendations
Upgrade Axios to version 1.20.0 or later where this vulnerability is fixed. No other mitigations are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-101906
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:26.10","Ubuntu:Pro:26.04:LTS"]
- Cvss Version
- 4.0
Threat ID: 6ad3f5002cdf04f656657bc8
Added to database: 10/17/2026, 22:21:52 UTC
Last enriched: 10/17/2026, 22:48:57 UTC
Last updated: 10/17/2026, 22:48:57 UTC
Views: 2
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